The overall purpose of the proposed research is to identify factors that promote quality of life in the chronically ill from which appropriate, cost-effective nursing interventions can be developed. The three specific aims of the project are: 1) to test a model of relationships among the major study variables, 2) to identify and systematically categorize physiological and psychosocial problems encountered and strategies used in adjusting to chronic illnesses, and 3) to assess the economic costs of chronic illness. A longitudinal study is indicated to evaluate changes and patterns in adaptation and quality of life as well as the financial burden for study subjects over time. The sample consists of 380 adults who have been diagnosed for at least one year with either insulin dependent diabetes mellitus (IDDM) or multiple sclerosis (MS). Data will be collected to measure the major study variables using a structured interview schedule, standardized instruments, and a diary where subjects document utilization of health care services and other treatment costs. Data will be collected during scheduled interviews at three different times approximately one year apart. Path analysis will be used to test the adequacy of the hypothesized model (study aim #1), comparative analysis will be used to identify similarities and differences in problems encountered and strategies used (study aim #2) and descriptive statistics will be used to analyze the financial burden of chronic illness for study subjects (study aim #3).